DESCRIPTION (applicant s abstract): The aim of this application is to permit the investigator with an opportunity to develop his career as an independent scientist in the biodemography of longevity. He has changed both his research approach (from studies of aggregated demographic life tables to the analysis of individual familial longevity records) and country of residence (immigrated to the United States from Russia). The investigator will undertake five years of training, study, research and career development to acquire enhanced research analytical skills in familial data analysis (event history analysis, multivariate survival analysis, multilevel modeling, population genetics), to strengthen his biosocial background and broaden his collaborative network with other U.S. investigators. His host organization, the Center on Aging at NORC/University of Chicago (UC), provides the investigator with an excellent working environment and strongly supports this application. In the proposed research, the investigator will fill a major gap in knowledge regarding long-term, postponed effects of delayed parenting on the life expectancy of adult offspring (life-shortening effects, expected from biological theories of aging). The specific aims of the proposed study are: (1) to determine whether persons born to older fathers have a shorter lifespan (expected as a result of the age-related accumulation of spontaneous mutations in paternal germ cells); to test his preliminary finding that only daughters born to older fathers have shorter lifespans (consistent with the critical importance of mutation load on the paternal X chromosome inherited by daughters only); (2) to analyze the maternal age effects on offspring longevity (in relation to the possible role of age-related accumulation of oxidative damage to mitochondrial DNA in maternal ova cells); (3) to examine the prediction of the X chromosome hypothesis that there should be a specific effect of late grandparental reproduction of maternal grandfathers only on grandsons' longevity; (4) to check the prediction of the parental support hypothesis that for longer lived parents the parental age effects will be less expressed. This research plan allows the investigator to acquire enhanced practical skills and research experience in advanced methods of multivariate statistics, data quality control and database management. The award allows the investigator not only to complete the proposed training and research projects, but also to develop a full-scale long-term research program in the biodemography of human longevity.